Better climate in African greenhouses for more output with less input

Greenhouse climate optimization should result in higher production levels with better quality and less use of pesticides and water. That's what Green Farming together with partners are showing with the project "Climate management in East African greenhouses". Svensson is one of the proud partners.

Green Farming is a Dutch programme that unites horticultural networks in the Netherlands, Kenya and Ethiopia. Green Farming sets up various demonstration projects together with local businesses and knowledge institutions to show which technologies, products, knowledge and services are available and how these can be applied to the local situation. Svensson is one of the project partners, delivering climate screens.

In the summer of 2014, the demonstration project ‘Climate management in East African greenhouses’ was put into practice at two farms in Kenya: Maridadi Flowers and Kreative Roses (Kordes).

Goal of the project

The purpose of the Green Farming Demonstration Project for greenhouse climate management is to realize a more favourable growing climate in greenhouses through the use of movable screening systems. Greenhouse climate optimization should result in higher production levels with better quality and less use of pesticides and water. Green Farming wishes to convince the East African horticulture sector that this technology, although having higher initial investment costs, will be most cost-effective and environmental-friendly in the long run because of the reduced use of inputs and the increased output.

Expected results

The expected results for the demonstration project are:

10 percent reduction in extreme temperature levels in the greenhouse.

10 percent reduction in extreme humidity levels in the greenhouse.

Reduction in the use of water (per stem) and crop-protection chemicals.

Reduction in the running costs.

Increase in annual production numbers by up to 20 percent.

Increase in product quality in terms of produced weights per square meter by up to 20 percent.

Increase in level of sustainability of the production system.

High grade light diffusion

A white climate screen with an open structure for enhanced light diffusion and shading, Ludvig Svenssons Harmony 3015 O has been chosen for the specific conditions in Kenya. The screen textile consists of white, transparent and open strips. The balance between the three determines the amount of radiation that is reflected, which for the screens used in these projects is 30 percent. It also determines the degree to which the screen diffuses the radiation. The white strips reflect part of the radiation and diffuse the part that goes through. The transparent strips allow all radiation through, but diffuse it. The open strips are applied for ventilation. The haze of the screening material used in these projects is 40 percent, which means that the textile diffuses 40 percent of the radiation that goes through. Total radiation is let through by 70 percent. The screen is installed horizontally as a hanging structure and slides over polyester support wires. The screen is linked to a computer with climate management software. With this software automated settings can be made for the amount of crop screening, in combination with adjusted irrigation. Based on weather data and climate recordings inside the greenhouse, the screen will be (partially) closed or opened to optimize the greenhouse climate.